DIN EN ISO 14129-1998 Fibre-reinforced plastic composites - Determination of the in-plane shear stress shear strain reponse including the in-plane schear modulus and strength by 45.pdf

1、DEUTSCHE NORM Februarv 1998 I DIN Fi bre-rei nforced plastic composites Determination of the in-plane shear stresshhear strain response, including the in-plane shear modulus and strength, by the f 45“ tension test method - English version (IS0 141 of 29 DIN : 1997) EN IS0 14129 I EN IS0 14129 ICs 83

2、.1 20 Descriptors: Plastics, fibre-reinforced plastic composites, testing. Faserverstrkte Kunststoffe - Zugversuch an 45O-Laminaten zur Bestimmung der Schubspannungs-/ Schubverformungs-Kurve und des Schubmoduls in der Lagenebene (IS0 141 29 : 1997) European Standard EN IS0 14129 : 1997 has the statu

3、s of a DIN Standard. A comma is used as the decimal marker. National foreword This standard has been published in accordance with a decision taken by CEN/TC 249 to adopt, without alteration, International Standard IS0 141 29 as a European Standard. The responsible German body involved in its prepara

4、tion was the Normenausschu Kunststoffe (Plastics Technology Standards Committee), Technical Committee Prepregs. DIN EN IS0 291 and DIN EN IS0 281 8 are the standards corresponding to International Standards IS0 291 and IS0 2818, respectively, referred to in clause 2 of the EN. National Annex NA Stan

5、dards referred to (and not included in Normative references and Annex ZA) DIN EN IS0 291 Plastics - Standard atmospheres for conditioning and testing (IS0 291 : DIN EN IS0 2818 Plastics - Preparation of test specimens by machining (IS0 2818 : 1994) 997) EN comprises 11 pages. No pari of this standar

6、d may be reproduced without the prior permission of V Deutsches Institut fr Nonung e. V., Berlin. Luth Verlag GmbH, D-10772 Berlin, has the exclusive right of sale for German Standards (DIN-Normen). Ref. No. DIN EN IS0 14129 : 1998-0 English price group 08 Sales No. 1108 07.98 EUROPEAN STANDARD NORM

7、E EUROPENNE EUROPISCHE NORM EN IS0 14129 December 1997 ICs 83.1 20; 83.1 40.20 Descriptors: Plastics, fibre-reinforced plastic composites, testing. English version Fibre-reinforced plastic composites Determination of the in-plane shear stresdshear strain response, including the in-plane shear modulu

8、s and strength, by the I45“ tension test method (IS0 141 29 : 1997) Composites plastiques renforcs de fibres - Dtermination de la rponse contrainte-dformation en cisaille- ment plan, module et rsistance compris, par essai de traction k 45“ (IS0 141 29 : 1997) Faserverstrkte Kunststoffe - Zug- versuc

9、h an 45O-Laminaten zur Bestimmung der Schubspannungs-/ Schubverformungs-Kurve, des Schubmoduls und der Schubfestig- keit in der Lagenebene (IS0 141 29 : 1997) This European Standard was approved by CEN on 1997-1 1-23. CEN members are bound to comply with the CENKENELEC Internal Regulations which sti

10、pulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national stand- ards may be obtained on application to the Central Secretariat or to any CEN member. The European Standard

11、s exist in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standard

12、s bodies of Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisch

13、es Komitee fr Normung Central Secretariat: rue de Stassart 36, 8-1050 Brussels O 1997. CEN - All rights of exploitation in any form and by any means reserved worldwide for CEN national members. Ref. No. EN IS0 14129 : 1997 E Page 2 EN IS0 14129: 1997 Foreword International Standard IS0 141 29 : 1997

14、 Fibre-reinforced plastic composites - Determination of the in-plane shear stresdshear strain response, including the in-plane shear modulus and strength, by the k 45” tension test method, which was prepared by ISO/TC 61 Plastics of the International Organization for Standardization, has been adopte

15、d by Technical Committee CEN/TC 249 Plastics, the Secretariat of which is held by IBN, as a European Standard. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by June

16、1998 at the latest. In accordance with the CENKENELEC Internal Regulations, the national standards organizations of the follow- ing countries are bound to implement this European Standard: Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxem

17、bourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, and the United Kingdom. Endorsement notice The text of the International Standard IS0 141 29 : 1997 was approved by CEN as a European Standard without any modification. Contents 1 2 3 4 5 6 7 8 9 10 11 12 Scope Normat ive referenc

18、es . Principle Definitions . Apparatus . Test specimens . Number of test specimens Conditioning Procedure . Calculation and expression of results . Precision . Test report Annex A Specimen preparation . Page 3 3 4 4 4 6 6 7 7 8 9 9 10 Introduction This International Standard covers all current and f

19、uture fibre-reinforced plastic composites which fail in the required manner. Harmonisation with the new tensile standard, IS0 527-5:1997, Plastics - Determination of tensile properties - Part 5: Test conditions for unidirectional fibre- reinforced plastic composites, has been achieved where relevant

20、 (e.g. document format, specimen size and related strains for modulus measurement). The test is acceptable for modulus but there is concern over its use for the ultimate shear strength for high shear-elongation materials due to the high strain at failure with only a small further increase in load, f

21、ibre rotation and associated temperature rise. Therefore, the stress at a maximum shear strain of 5 % or less is used as the failure criterion. This failure criterion is also used in ASTM D 3518 (1995). Page 3 EN IS0 14129 : 1997 1 Scope 1 .i This International Standard specifies a procedure for det

22、ermining the in-plane shear stressshear strain response, including the in-plane shear modulus and shear strength, of fibre-reinforced plastic composites by the f 45“ tension test method. 1.2 The method is suitable for use with thermoset and thermoplastic matrix laminates made from unidirectional lay

23、ers and/or fabrics including unidirectional fabrics, with the fibres oriented at k 45 to the specimen axis, where the lay-up is symmetrical and balanced about the specimen mid-plane. NOTE - The method is not suitable for coarse fabrics. 1.3 As the test has been shown to be sensitive to the number an

24、d distribution of layers, comparisons should be undertaken using the same number of layers, which must be well distributed. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of pu

25、blication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain reg

26、isters of currently valid International Standards. IS0 291 :I 997, Plastics - Standard atmospheres for conditioning and testing. IS0 1268:1974, Plastics - Preparation of glass fibre reinforced, resin bonded, low-pressure laminated plates or panels for test purposes.) IS0 2602:1980, Statisfical inter

27、pretation of fest results - Estimation of the mean - Confidence interval. IS0 281 83994, Plastics - Preparation of test specimens by machining. IS0 5893:1993, Rubber and plastics test equipment - Tensile, flexural and compression types (constant rate of traverse) - escripfion. 1) Under revision. Pag

28、e 4 EN IS0 14129: 1997 3 Principle A test specimen consisting of a strip of rectangular cross-section with the fibres oriented at k 45” to the specimen axis is loaded in tension. To determine the shear modulus the strains parallel and perpendicular to the specimen axis are measured. The test is term

29、inated at y,2 = 0,05 if failure (excluding premature failure at or within the grip) has not occurred. NOTE- Although this test method can establish shear stress/shear strain response well into the nonlinear region, the ultimate stress and strain values so obtained should be evaluated with the follow

30、ing caution. The material in the gauge section of this specimen is not in a state of pure shear, as normal stress components are present, even in the rotated ply coordinate system. It has been established that when a +45” laminate is loaded in tension, normal stress components, though small, general

31、ly decrease the calculated ultimate stress and strain values of the material below the actual capability of the material, thus resulting in lower values of ultimate strength and strain than those obtained by more ideal methods, such as the tube torsion test. 4 Definitions For the purposes of this In

32、ternational Standard, the following definitions apply: 4.1 specimen cross-sectional area. It is expressed in megapascals (MPa). in-plane shear stress, T,: The shear stress obtained by dividing the instantaneous load by twice the 4.2 in-plane shear strength, qZM: The maximum in the shear stress prior

33、 to or at termination of the test at y12 = 0,05. It is expressed in megapascals (MPa). 4.3 shear strain, y,*: The sum total of strain in the direction parallel and perpendicular to the specimen axis, .e. (E, - Fi). NOTE - E, has an negative sign when E, is positive. 4.4 in-plane shear (chord) modulu

34、s, G,2: The shear stress difference (q2” - 2,;) divided by the corresponding shear strain difference (y,; = 0,005 - y,; = 0,001) see 10.3, equation (3). It is expressed in megapascals (MPa). 4.5 specimen coordinate axes: For the specimen shown in figure 1, the direction parallel to the specimen long

35、itudinal axis is the “x” direction and the direction perpendicular to it is the :y” direction. The fibres are oriented at f 45” to these directions. The coordinate axes for a unidirectional reinforced composite material plate element are shown in figure 2. 5 Apparatus 5.1 Test machine 5.1.1 General

36、The machine shall conform to IS0 5893 as appropriate to the requirements given in 5.1.2 and 5.1.3. 5.1.2 Speed of testing The speed of testing v shall be kept constant in accordance with IS0 5893. Page 5 EN IS0 14129 : 1997 Dimensions in rnillimetres 2 / Key 1 Strain gauges 2 Tab 8 Fibre angle (= 45

37、“) Specimen thickness h = 2 mm Figure 1 - Fibre-reinforced plastic composite specimen showing fibre axes t Figure 2 - Unidirectional reinforced composite plate element showing symmetry axes 5.1.3 Load indicator The load indicator shall be such that the error in the indicated force is less than I1 Yo

38、 of the full-scale reading (see IS0 5893). 5.2 Strain measurement The procedure requires the strain to be measured both parallel and perpendicular to the specimen axis. Strain gauges, applied as in figure 2, or extensometers shall be accurate to k 1 Yo of the full scale. The gauges, surface preparat

39、ion and bonding agents shall be chosen to give adequate performance on the subject materials, and suitable strain-recording equipment shall be employed. 5.3 Micrometer, or equivalent, capable of reading to 0,Ol mm or less, and suitable for measuring the thickness h and width b of the test specimen.

40、The micrometer shall have contact faces appropriate to the surface being measured (.e. flat faces for flat, polished surfaces and hemispherical faces for irregular surfaces). Page 6 EN IS0 14129: 1997 6 Test specimens 6.1 Shape and dimensions The specimen shall have a width of 25 mm I0,5 mm and a le

41、ngth of 250 mm. Unless otherwise specified, the thickness shall be 2 mm f 0,2 mm. The longitudinal edges of individual specimens shall be parallel to within 0,2 mm. The dimensions of the specimen are shown in figure 1. For materials made with layers thicker than 0,125 mm, the laminate shall consist

42、of 16 layers. 6.2 Preparation of specimens 6.2.1 General A panel shall be prepared in accordance with IS0 1268 or another specified/agreed procedure with the required balanced and symmetrical _+ 45“ fibre orientation. Cut individual specimens or groups of specimens to the required size. Some paramet

43、ers for machining are specified in IS0 2818. Further guidance on cutting specimens is given in annex A. 6.2.2 End tab material Providing failure does not occur at or within the grip, unbonded tabs or no tabs may be used. If tabs are used, they shall be constructed from a cross-ply or fabric laminate

44、 made of glass-fibrehesin, or from the material under test, with the fibre axes of the fabric set at k 45“ to the specimen axis. The tab material thickness shall be between 0,5 mm and 2 mm, with a tab angle of 90“ (.e. not tapered). 6.2.3 Application of end tabs Bonded end tabs, if used, shall be ap

45、plied to the specimen with a high-elongation adhesive, as shown in annex A. NOTE - A similar procedure can be used for individual specimens or for a group of specimens. 6.2.4 Machining the specimens The test specimens shall be cut with their axis at 45“ to the fibre directions. 6.3 Checking the test

46、 specimens The specimens shall be flat and free of twist. The surfaces and edges shall be free from scratches, pits, sink marks and flashes. The specimens shall be checked for conformity to these requirements by visual observation against straight-edges, squares and flat plates, and by measuring wit

47、h micrometer callipers. Specimens showing measurable or observable departure from one or more of these requirements shall be rejected or machined to the required size and shape before testing. 7 Number of test specimens 7.1 At least five test specimens shall be tested. The number of measurements may

48、 be more than five if greater precision of the mean value is required. It is possible to evaluate this by means of the confidence interval (95 % probability, see IS0 2602) Page 7 EN IS0 14129 : 1997 7.2. The results from test specimens that rupture at or inside the grips or end tabs shall be discard

49、ed and new specimens tested in their place. 8 Conditioning Where applicable, condition the test specimens as specified in the standard for the material under test. In the absence of such information, select the most appropriate conditions from IS0 291, unless agreed otherwise by the interested parties. 9 Procedure 9.1 Test atmosphere Where applicable, test the specimen as specified in the standard for the material under test. In the absence of such information, select the most appropriate conditions from IS0 291, unless agreed otherwise by the interested parti